An HPLC method for quantifying the 3-hydroxypyridinium crosslinks of collagen is described. It can be applied to crude hydrolysates of all types of connective tissue. Mineralized tissues can be hydrolyzed directly and analyzed without interference from the mineral ions. The hydroxylysyl (HP) and lysyl (LP) forms of hydroxypyridinium residue were resolved on a reverse-phase C18 column using a gradient of acetonitrile in water and 0.01 M n-heptafluorobutyric acid as an ion-pairing agent. The… CONTINUE READING